Relapse is associated with a poor prognosis among drug users. Crack cocaine users are more prone to severe dependence because of the intensity of use. Additionally, initiating drug use during adolescence worsens users' prognosis due to the increased rates of impulsivity and other risk behaviors. This study aimed to identify the predictors of early relapse among adolescent crack users discharged from inpatient treatment. A cohort study was conducted with 89 psychiatric inpatients aged 12-17 years from two different hospitals in southern Brazil who met the criteria for crack abuse or dependence. Demographic data, substance use disorders, psychiatric comorbidities, and crack consumption profile were assessed during hospitalization using the Teen Addiction Severity Index, Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime, and Crack Consumption Profile. Participants were re-assessed at 1 and 3 months after hospital discharge to determine their crack cocaine use based on self-report, family/caregiver information, and urine tests, whenever possible. There were extremely high rates of relapse (valid percent) in the first and third months, 65.9 and 86.4%, respectively. Statistically significant associations were observed between relapse in the first month and length of cocaine/crack cocaine use, and length of hospital stay. Data at 3 months were not analyzed because of the small number of patients who did not relapse. The high rates and significant associations found in this study suggest that intensive outpatient treatment strategies targeting this population should be developed and implemented to prevent early relapse after detoxification. One of the possible approaches, based on recent studies, might explore motivation as a strategy to reduce the rate of early relapse.